Determination of Uranium Content in Dental Porcelains by Means of the Fission Track Method and Estimation of Radiation Dose to Oral Mucosa by Radioactive Elements

Abstract

Porcelain teeth, some of which contain uranium compounds for aesthetic purpose, have been widely used in dental clinics. Hazardous effects due to uranium radiation have been suggested in recent publications. In the present study, the authors carried out the determination of uranium concentrations in four major brands of porcelain teeth marketed in Japan using the fission track method, and the absorbed doses to oral tissues were calculated by a formula introduced by the authors for calculation of alpha radiation. Average uranium concentrations of the brands studied were determined to be 3.6 ppm (0.33–10 ppm, Japan), 18 ppm (0.69–81 ppm, Japan), 9.4 ppm (2.5–14 ppm, Japan) and 82 ppm (11–205 ppm, U.S.), respectively. The corresponding dose equivalents at the surface of oral mucosal membrane were 2.9 rem yr −1, 14 rem yr −1, 7.6 rem yr−1 and 66 rem yr−1.